1. Field of the Invention
The present invention relates generally to an assembly for connecting conduit to a component. More specifically, this invention relates to a mechanism for detecting a leak or absence of a seal after connecting a conduit to a component, such as a connection block or an expansion valve, of a pressurized fluid system.
2. Description of Related Art
Modern automotive air conditioning systems generally include a compressor, condenser, evaporator, expansion valve and a plurality of conduits or lines that connect the various components. A suitable refrigerant is contained within the system. Installation of the various air conditioning system components is typically independent of one another with the conduit connected to the components after they are installed or mounted to the vehicle. While different methods and apparatuses for securing the conduit to the various components are known, one method utilizes an o-ring encircling an end of conduit that provides a seal when the end of the conduit is secured in a port on the component.
To secure the end of the conduit to the component, a connection plate engages and traps the conduit in a conduit passage extending through the plate. The connection plate further includes a second passageway offset from and parallel to the conduit passage. Once the conduit is inserted into a port on the component, a fastener extending through the second passageway secures the connection plate to the component whereby the end of the conduit is connected to the component.
Vehicle space limitations and packaging consideration sometimes make it difficult for an assembler to attach the conduit to the various components due to their location on the vehicle. In addition, mass production constraints, wherein the vehicles are traveling rapidly on an assembly, limit the time provided to connect the conduit to the various components. Thus, during or prior to the assembly process and unbeknownst to the assembler, the o-ring may be damaged or missing from the end of the conduit. Accordingly, the conduit may be installed to the component with a damaged o-ring or without the o-ring.
To insure the system is properly assembled, the system undergoes a leak test prior to filling the system. The leak test typically involves the use of a vacuum leak testing system that draws a vacuum on the system and monitors the level and hold time of the vacuum. Accordingly, an air conditioning system may ultimately pass the leak test even though the o-ring is damaged or missing. For example, in some instances the connection plate provides sufficient pressure on an annular bead or upset portion of the conduit to compress it against the component thereby forming a temporary or limited seal. Such a seal results in a slow leak. The leak detection system may not detect such slow leaks resulting in the system passing the leak test and being filled with refrigerant. Over time, the refrigerant leaks out and the system ceases to work, resulting in warranty concerns along with expensive and time-consuming repairs.
Accordingly, it is desirable to provide a conduit to component fitting assembly having a leak detection mechanism that cooperates with the leak detection system to detect a missing or damaged seal member upon or at the initial leak detection step and prior to filling the system with refrigerant.